+129852 14a^3- 3/a^2=426 [ I'll use "x" instead of "a" ]
14^x^3 -3/x^2 - 426 = 0 multiply through by x^2
14x^5 - 3 - 426x^2 = 0
14x^5 - 426x^2 - 3 = 0
This does not have an algebraic solution, DP [ or, at least, I don't think that it does ]
There is only one real root at x = a ≈ 3.12
There are also 4 complex roots
Here is the graph and solution found by WolframAlpha :
https://www.wolframalpha.com/input/?i=14x%5E5+-+3+-+426x%5E2+%3D+0
+129852 16/n^2 * 2.352 = 425.32
Divide both sides by 2.352
16/n^2 = 425.32 / 2.352 and we can write
n^2 /16 = 2.352 / 425.32 multiply both sides by 16
n^2 = 16*2.352 / 425.32 take both roots
n = ±√ [ 16* 2.352 / 425.32] ≈ ± 0.297
Here is the graph : https://www.wolframalpha.com/input/?i=16%2Fn%5E2%C2%A0*+2.352+%3D+425.32
